1. Field of the Invention
The present invention relates to a display device and more specifically to a double-screen display device on which information such as images, drawings, graphs, documents, etc. are displayed when at least two persons have discussions face to face with each other by referring to the information displayed on the device.
2. Description of the Related Art
The display unit of the conventional display device has a single screen, and is normally designed to be mounted vertically. The display format of the display unit is, for example, opening a plurality of windows on a single screen to separately display images, documents, numerical characters, etc. on each window.
However, the conventional display device is designed and installed to allow only a single operator to exclusively refer to its screen and perform various processes. Some display devices are provided with display units to be mounted such that the screens can be set horizontal. Such display devices have been exclusively developed to personally play game on, but is not designed to allow a plurality of persons to simultaneously watch the screen from various directions.
Recently, personal computers (including desktop and portable computers) and workstations are popularly used in conferences to replace the printed materials distributed to attendants of conferences or the overhead projectors (OHP). To support this tendency, various presentation tools have been introduced by utilizing large capacity storage media in electronic, optical, electromagnetic, and combination of these storage methods.
With these presentation tools, the large capacity storage media store document and image data so that various information can be effectively displayed by switching and simultaneously displaying the data on the screen by the screen switching, screen segmenting, and multiple window methods on the screen of, for example, the cathode ray tube (CRT) display, liquid-crystal display, plasma display, projector, etc.
The information material to be used in explaining a given subject in a conference can be actually generated by such presentation tools, but is displayed on the conventional vertically-fit display screens. Common projectors can satisfactorily work in, for example, a lecture meeting where a large number of attendants simultaneously watch the same material displayed on the screen. However, if the projector is used in a conference room by a small number of attendants, the attendants have to rush shoulder to shoulder in front of the small screen of a projector, and some attendants cannot watch the screen at all. With such a layout of the seats of the attendants, they cannot concentrate on the explanation and discussion because they sit too close to one another to watch the display.
When a number of attendants have a meeting and discussions, it is desired that they sit face to face with a table between them. Accordingly, the conventional display devices cannot be used to solve the problem.
Normally, customers access the counters and windows of financial organizations, tourist bureaus, official organizations, government offices, various festivals and meetings, ticket boxes, etc. In such cases, the vertically-fit display can be fit horizontally. However, the customer and the server watch the information material in the opposite directions to each other. Therefore, one can watch the material in the right direction, but the other has to watch it upside down. If the material is text data, the other person has difficulty in reading the text.
To solve the above described problems, Tokukaisho 53-136434, Tokukaisho 58-002881, and Tokukaihei 03-140995 are laid open by the Japanese Patent Office to public inspection.
Tokukaisho 53-136434 disclosed in the official publication discloses the technology of displaying an image on both sides of the screen. The image is displayed double as inverted on the left and right windows on each screen so that the same image can be viewed by the customer and the server. Tokukaisho 58-002881 and Tokukaihei 03-140995 disclose the technology of providing image memory for each screen, writing images opposite to each other (an original image and its 180-degree-rotated image), and displaying the two images by switching them when necessary so that the two persons can view the same normal image on each seat.
However, the screen of Tokukaisho 53-136434 according to the official publication disturbs the communications between the two persons. Tokukaisho 58-002881 and Tokukaihei 03-140995 have the problem that the images viewed by the two persons are inverted to each other and need switching into the 180-degree-inverted image when explanation is given from one to the other. If the image is symmetrically rotated by 180 degrees each time the explanation is given, the two persons have to recognize the images each time they are switched, thereby preventing them from concentrating on the explanation itself.
Therefore, instead of displaying the material on the display screen, the photographic material such as catalogs is used with explanatory text and price lists. However, they are separate pamphlets and rather heavy when sales persons carry them to visit their customers. They also occupy large space on the table and makes a messy table.